Precious stone



FIG. 1 is a top view of a precious stone, showing my new design;

FIG. 2 is a right view thereof;

FIG. 3 is a left view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a rear view thereof; and,

FIG. 6 is a font view thereof.

The ornamental design for a precious stone, as shown.